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The Thujone Connection

To a great extent, absinthe owes its notorious reputation
to a chemical called thujone (pronounced thoo-ZHONE). Thujone is a monoterpene,
related to both camphor and menthol, that occurs naturally in wormwood as well
in sage, tarragon, tansy and commercial products such Vicks VapoRub. Classified
as a convulsant poison by the U.S. Food and Drug Administration, thujone is often
cited as the source of absinthe's toxicity as well as the source of its alleged
psychoactive properties.

The emphasis on thujone as the active ingredient of absinthe has persisted
largely because conventional wisdom held that vintage pre-ban absinthes contained
far more thujone that the concentrations allowed under contemporary European
law. In the 1990s, the European Community Codex Committee on Food Additives
set a limit of 10 mg/kg of thujone in alcoholic beverages. The decision essentially
legalized absinthe across Europe, although other restrictions on its production
vary from country to country. (In the United States, the Federal Food, Drug
and Cosmetic Law of 1972, which superseded Food Inspection Decision 147, prohibits
detectable levels of thujone in finished products, thus maintaining absinthe's
restricted status in America.)

In a widely read article, Wilfred Niels Arnold, a professor of biochemistry,
speculated that pre-ban absinthes contained as much as 260 mg/kg of thujone.
By contrast, at a measly 10 mg/kg, contemporary European brands appeared to
be pale reflections of the potent pre-ban brands. In the minds of many, thujone
content became the index of an absinthe's quality and authenticity.

No one, apparently, had ever bothered to actually test pre-ban absinthe. Enter
Ian Hutton. Hutton, a British dealer in Belle Epoque antiques and absinthe aficionado,
became acquainted with Emile-Gerard Pernot, great-grandson of the founder of
the Emile Pernot distillery in Pontarlier. With the recent easing of France's
absinthe laws, Pernot had begun producing absinthe again at the family's distillery,
although by French law at the much-reduced strength of 90 proof. Hutton commissioned
Pernot to produce for export a traditional absinthe using the old family recipe
and at the vintage strength of 136 proof. The problem, Hutton feared, was that
based on Arnold's calculations, the traditionally made product would far exceed
EU thujone restrictions.

Hutton commissioned a gas-liquid chromatography (GLC) analysis of the custom
product as well as a sample of pre-ban Pernod Fils to determine their thujone
content. The results were shocking. Vintage Pernod Fils, the Holy Grail of absinthes,
contained not 260 mg/kg of thujone but a mere 6 mg/kg. Un Emile 68, the custom
absinthe, contained 10 mg/kg. "When we saw the results, we couldn't believe
them," Hutton says. "The high levels quoted turned out to be based on wrong
information that had been repeated over and over."

The results of the GLC analysis, published in September 2002 in the journal
Current Drug Discovery, shot down once and for all the contention that
pre-ban absinthes were somehow more potent than contemporary brands and that
traditionally made products couldn't be produced under EU guidelines. It also
enabled Hutton to begin importing Un Emile 68 to the United Kingdom. Today,
many consider Un Emile to be the finest of the recent crop of artisanal absinthes
produced since the loosening of European laws.

As for thujone's reputation as the psychoactive component of
absinthe, Ted Breaux is unequivocal: "Thujone is not a drug," he says. "It doesn't
behave like a drug. It's not a psychoactive, psycho-hallucinogenic compound.
And even it were, it would have to have the pharmacological potency of morphine
to be effective in the concentrations we're talking about. It doesn't."

click to enlarge

Thujone occurs naturally in wormwood (pictured) and is often cited as the source of absinthe's toxicity and psychoactive properties.